1. Field
The field of the invention is devices for loosening and chopping the upper layer of snow in paths for skiing, and more particularly the rotating snow cutting components thereof and the outstanding snow cutting teeth mounted on such components.
2. State of the Art
The tilling of snow upon slopes for skiing has employed such devices as agricultural harrows comprising a field of downstanding spikes and agricultural cultivators comprising disks mounted upon rotating bars to cut and churn the snow. Later, other rotating bar devices carried multiplicities of radially extending spikes. Short sections of chains have been tried. The cutter bars are rotated by power supplied by a towing vehicle, passing over the snow as it tills the path. Spikes were generally sharply pointed but dull of edge and were easily bent, and were soon replaced by teeth comprising generally rectangular steel plates arranged with edges cutting into the snow. Such teeth provided greater strength to resist tangentially directed forces. Soon the leading plate edges were sharpened for greater effectiveness and lower power expenditure. Then, the flat plate teeth were fixed angularly to the cutter bar, presenting a forwardly facing surface component. This increased the snow stirring and crushing action of the teeth. However, with the angular attachment mode, the relatively thin plates became subject to side bending loads, presenting other structural problems. To at the same time preserve the cutting and stirring functions and provide substantial side bending resistance, the individual teeth were bent along centerlines thereof. The resulting bent or angled tooth was affixed so that one-half of it directly cut into the snow without angle, while the remaining half protruded into the snow.
Advantageous as were the bend angle incorporating rectangular cutting teeth, competing needs for strength and for relatively small snow piercing tips lead to the adoption of teeth that were roughly trapezoidal in side profile. The teeth each joined the cutter bar at a broad base, but narrowed substantially to the cutting tip. The trapezoidal shape was then altered to incorporate a pair of snow piercing ears at the tip, the leading one of which aggressively chopped into crusted snow. The broadened base however carried unwanted weight of steel not significantly contributing to structural strength.
The need therefore still existed for a strong snow cutting tooth for attachment to a tiller cutter bar, which has an extended base, and an efficient snow cutting tip, but does not add excess weight resulting from the use of nonfunctional structural material therein.